i had a bunch of scuffs from lane splitting in stopped traffic. random yellow marks from NYC cabs, and little white scuffs from the random toyota. I'm pretty sure no german cars were hurt :) i figured out how to remove them today, and clean the cases.
the magic eraser by mr. clean is amazing. I've been using it to take scuffs out of walls for years. a tiny bit of water and some rubbing would solve almost all wall problems.
i tried it on the vario cases and it worked just as well. the only issue is that the white juice that comes out of it can stain the case if you don't clean it up soon after. so rub away, and after your cases will look filthy covered in white juices. quickly get a wet paper towel and rub down the case. repeat as needed getting out all the scuffs.
then when you're done, get some rubbing alcohol and a rag and wipe the entire case down for a nice clean shine. the alcohol cleaning is actually great. using alcohol swabs you can see the dirt coming off.
see the attached photos to see the before and afters.